At this point we have the basic facts in the Bush wiretapping issue. The FISA courts will not only issue warrants, they will issue retroactive warrants up to 72 hours after an agent has listened in on a conversation. The President did choose to authorize warrantless wiretaps out of any need to protect America, our agencies can protect America just fine by obeying the law and getting warrants. The logical question is why did our only President choose, not just once but over a dozen times, to violate the 4th Amendment and allow warrantless searches of American citizens?
The answer lies in accountability and responsibility; President Bush, one of the most secretive men to ever hold the office, seems to be essentially opposed to both.
The purpose of a warrant is to build a paper trail describing what an agent of the law did. Generally the courts, especially FISA, will issue a warrant for the asking. Let me emphasize here: the primary purpose of the requirement that a law enforcement agent get a warrant before searching a citizen is not to provide judicial oversight for his justification for that search. The most important aspect of the warrant system is that it builds a paper trial saying "agent X searched person/place Y". Later if it turns out that agent X requested the warrant for insufficient reasons this paper trail can be used in proceedings against him. Later if it turns out that agent X has a history of searches that don't turn up any evidence of wrongdoing the paper trail of the warrant requests can be used to justify firing him. The warrant paper trail is there to help us keep our law enforcement officers in line because they know that if they abuse their power to search and seize there will be a record of those abuses and they will be held accountable for their actions.
That is why President Bush wants warrantless searches, because he wants an end to accountability. Somewhere in some secret NSA file there may be a record of which agents decided to wiretap American citizens, but unlike warrants those records can, and will, be buried and we will never see them. The accountability aspect has been removed completely, and secure in the knowledge that they will never be held responsible for their actions the law enforcement agents will slowly begin to act less responsibly.
It is entirely possible that every single warrantless wiretap performed under President Bush's plan was necessary and proper, but since the records of who requested the wiretaps and why will never be public we will never know, and that is the true problem with warrantless wiretaps. We will never know if they were proper, or not. We will never know who was responsible for them. We will never know if the people performing the wiretaps did so to defend America, or if they did so to spy on their political enemies.
That lack of knowledge is exactly what President Bush seems to want. Like so many other actions taken by his administration this action seems to be based on the idea that the American people should not know what their government is up to. We need warrants, if for no other reason, because they are a tool to let Americans know what their government is doing.